Rectangular-duct forming machine

ABSTRACT

A machine designed to continuously progress a pair of elongated flat sheets of metal longitudinally through a plurality of cooperative dies which progressively in sequential steps gradually shape the two sheets into a duct having a rectangular cross-sectional configuration. The machine utilizes cooperative rotary dies to shape and form the duct in a continuous operation to a length equal to that of the sheets so that rectangular ducts of any desired length can be produced in an automatic operation by merely inserting into the machine a preprepared roll comprised of a pair of sheets of metal of the desired length, the sheets entering the machine at one end and leaving the same at the other end in the form of a continuous rectangular duct.

ilrtited States Patent Anderson et al. {4 1 Jan. 25, 1972 [54]RECTANGULAR-DUCT FORMING 3,407,640 10/1968 Lipp ..72/18] A I M CH NEFOREIGN PATENTS OR APPLICATIONS [72] Invent: i gg g fffgg gf bmh 723,9082/1955 Great Britain 72/52 385,642 11/1923 Germany ..1 l3/54 [73]Assignee: Snappy, lnc., Detroit Lakes, Minn.

, Primary Examiner-Richard J. Herbst {22] Fllcd: 1970 AtlameySchroeder,Siegfried & Ryan [Zll Appl. No.: 12,663

[57] ABSTRACT 52 us. c1 ..113/54, 29/200 B, 72/52, A machine designed tocontinuously progress a P of 6101* 72 1 1 gated flat sheets of metallongitudinally through a plurality of 511 1m. (:1 ..B21d 39 02cooperative dies which progressively in Sequential steps 58 Field ofSearch ..1 13/54; 72 51, 52, 181; gradually Shape the two Sheets into aducthavihg a rectangular 29 200 B 4 3 429 203 D cross-sectionalconfiguration. The machine utilizes cooperative rotary dies to shape andform the duct in a continuous 5 References Cited operation to a lengthequal to that of the sheets so that rectangular ducts of any desiredlength can be produced in an auto- UNITED STATES PATENTS matic operationby merely inserting into the machine a preprepared roll comprised of apair of sheets of metal of the desired length, the sheets entering themachine at one end and :9 4/1970 55 B leaving the same at the other endin the form of a continuous 489,498 1/1893 Pruden ..72/52 rectangularduct 2,682,850 7/1954 Close .72/5l 32 Claims 32 Drawing Figures PATENTEDJAN 2 51972 SHEET OIUF 10 PATENTEDmzsmz 31636303 sum 08 or 10 BY650440,] MUN/V RECTANGULAR-DUCT FORMING MACHINE This invention relatesto heating ducts. More particularly, it relates to machines for formingelongated metal ducts having a rectangular cross-sectionalconfiguration.

There is a vast demand today for elongated metal ducts which aregenerally rectangular in cross-sectional configuration. This isparticularly true in the heating industry and especially true withrespect to the manufacture of mobile homes. The manufacture ofrectangular heating ducts has posed a substantial problem for a longtime, particularly where the duct is to be quite extensive in length, aswill be realized from the description hereinafter of the method by meansof which such ducts have been formed.

The conventional manner of producing rectangular heating ducts hasheretofore involved first the selection of a flat sheet of metal of thedesired length of the heating duct, provided such length was not toogreat to make proper handling of the sheet possible. Where relativelylong lengths of heating duct were required, such ducts were made inshorter sections and then subsequently secured together. This wasparticularly true where the ducts had to be transported from thelocation of manufacture to the location of installation. To manufacturethe heating ducts, the flat sheet was formed with a male lock at oneedge and a female lock at the opposite side edge, and thereafter theelongated sheet was bent simultaneously throughout its length to impartthe rectangular shape and to bring the male and female edges together,preparatory to moving them into mating relation. The final step involvedthe insertion of the male into the female lock to lock the same to eachother. Great difficulty has been experienced in assembling these locks,the main problem being the fact that the male or female edge isfrequently bent inadvertently during the efforts involved in shaping theflat sheet into the desired rectangular shape, and as a consequence,great difficulty is experienced in bringing the two edges into propermating relation The length of such sections is obviously limited becauseof these difficulties. Since a duct of any appreciable length must beassembled section by section if it is to be manufactured by the methodsheretofore known, a great expenditure of time, effort, and materials isinvolved in the manufacture of ducts having appreciable length by thesemethods.

It is a general object of our invention to provide a machine constructedand arranged to continuously form an elongated duct having a rectangularcross-sectional configuration from a pair of flat sheets of metal fedinto the machine simultaneously.

A more specific object is to provide a machine constructed and arrangedto continuously progress a pair of elongated sheets of flat metalthrough the machine and automatically form therefrom, in continuousprogression, a duct having a rectangular cross-sectional configuration Amore specific object is to provide a novel machine having a plurality ofcooperating rotary dies mounted in spaced relation along the length of asupporting frame and adapted to receive and progressively shape alongtheir length a pair of elongated flat sheets of metal, in sequentialsteps, into a duct having a rectangular cross-sectional configuration.

Another object is to provide a machine constructed and arranged toreceive and continuously progress a pair of elongated flat sheets ofmetal therethrough, the sheets being formed by and leaving the machinecontinuously in the form of a duct having a rectangular cross-sectionalconfiguration, the forming of the duct being accomplished through aseries of partial progressive bending steps accomplished sequentiallythrough the use of rotary dies at points spaced along the length of thesheets while they are passing through the machine.

Another object is to provide a novel machine constructed and arranged toenable a duct manufacturer to rapidly and efficiently produce elongatedducts of rectangular cross-sectional configuration of any predeterminedlength by merely feeding into the machine a pair of flat sheets of metalprecut to the same predetermined length.

Another object is to provide a novel machine constructed and arranged tomanufacture rectangular ducts of any predetermined length at a verysubstantial saving in time, labor and costs.

Another object is to provide a novel machine constructed and arranged tomanufacture rectangular ducts automatically at great saving, the machineitself being compact, automatic in operation, inexpensive tomanufacture, troublefree in operation, and inexpensive and simple tooperate and maintain.

Another object is to provide a portable machine which permits users ofrectangular ducts s'uch asmobile home manufac-v turers to manufacturetheir duct needs in single sections of desired length, whatever they maybe, at their operations base, to thereby eliminate the need fortransporting preformed tubular sections thereto.

Another object is to provide a novel machine which constructsrectangular tubular ducts from pairs of flat sheets of metal in anautomatic operation which produces an end product having improvedquality and performance characteristics.

Another object is to provide a machine which automatically constructsrectangular ducts from pairs of flat sheets of metal and which obviatesthe heretofore need of forming such ducts by bending the material fromwhich the duct is to be made simultaneously throughout its length andwhich obviates the great difficulties heretofore encountered inassembling the male and female locks utilized in the known conventionalmanufacturing methods of ducts so shaped.

These and other objects and advantages of our invention will more fullyappear from the following description, made in connection with theaccompanying drawings, wherein like reference characters refer to thesame or similar parts throughout the several views, and in which:

FIG. 1 is a diagrammatic plan view of the preferred form of ourinvention with stations indicated thereon and without theseam-flattening mechanism being included;

FIG. 2 is a diagrammatic side elevational view of the embodiment shownin FIG. 1;

FIG. 3 is a diagrammatic vertical sectional view taken through stationNo. l of the embodiment shown in FIG. 1;

FIG. 4 is a diagrammatic vertical sectional view taken through theembodiment shown in FIG. 1, at station No. 2, and illustrating how theoutermore lateral portions of the two sheets are shaped preliminarilytoward becoming cooperative seam elements;

FIG. 5 is a diagrammatic vertical sectional view taken through theembodiment shown in FIG. I, at station No. 3, and illustrating themanner in which the innermore lateral portions of the two sheets arecrimped preliminarily to bending each sheet into oppositely facingchannel members and the outermore lateral portions are shaped finallyinto seam elements;

FIG. 6 is a diagrammatic vertical sectional view taken through theembodiment shown in FIG. 1, at station No. 4, and illustrating themanner in which the lateral portions are guided inwardly at the beadline about the fixed die and into the adjacent and following rotary diemembers;

FIG. 7 is a diagrammatic vertical sectional view taken through theembodiment shown in FIG. I, at station No. 5, and illustrating themanner in which the rotary dies cooperate with the fixed die at the beadline and present the outermore lateral portions of the lower sheettoward the corresponding portions of the upper sheet;

FIG. 8 is a diagrammatic vertical sectional view taken through theembodiment of FIG. 1, at station No. 6, and illustrating the manner inwhich the guide rollers bend the lateral portions of the sheets furtherinwardly about the bead line and present the lower seam elements to theupper seam elements at an inwardly disposed position to facilitatesubsequent interengagement;

FIG. 9 is a diagrammatic vertical sectional view taken through theembodiment shown in FIG. I, at station No. 7, and illustrating themanner in which the cooperative rotary members complete the bend at thebead lines to and commence closing the same; i

FIG. is a diagrammatic vertical sectional view of the embodiment shownin FIG. 1, taken at station No. 8, and illustrating the cooperativecamming members closing the seam by camming the overlying seam lip ofthe upper sheet into parallel and underlying relation to the edgeportions of the lower sheet;

FIG. 11 is a diagrammatic vertical sectional view taken through theembodiment shown in FIG. I, at station No. 9, and illustrating thefinishing operation in which the seam is compressed and buttoned topositively lock the seam elements together;

FIG. 12 is a diagrammatic perspective view illustrating how the two fiatsheets are taken from a single roll by the embodiment shown in FIG. 1and progressively formed into a duct having a rectangularcross-sectional configuration, the respective station numbers beingindicated thereon at the point at which the two sheets take the shapesindicated thereat;

FIG. 13 is a diagrammatic side elevational view of the controls for thefeeding mechanism and initial forming rollers at station No. 1;

FIG. 14 is a diagrammatic side elevational view showing the springloading provided for the upper set and lower set of rollers of thefeeding mechanism and initial forming dies at station No. 1;

FIG. 15 is a diagrammatic detailed perspective view of the seam cammingmembers shown in FIG. 10;

FIG. 16 is a detailed diagrammatic view, shown on an enlarged scale, ofthe huttoning operation of the rotary dies shown in FIG. 11;

FIG. I7 is a diagrammatic vertical sectional view of a rectangular-ductforming machine constructed similarly to the embodiment shown in FIGS.1-16, with the exception that its dies are constructed and arranged toform the seams at the comers of the duct rather than at a pointintermediate the corners, the view being taken at station No. 1 with therollers in separated position;

FIG. 18 is a diagrammatic vertical sectional view of the embodimentidentified in the description of FIG. 17 and taken at station No. 2thereof;

FIG. 19 is a diagrammatic vertical sectional view taken at station No. 3of the embodiment identified in the description of FIG. 17 andillustrating the forming of the 90 lip at the extreme lateral portionsof the wider sheet and the initial break at the innermore lateralportions thereof;

FIG. 20 is a diagrammatic vertical sectional view taken at station No. 4of the embodiment identified in the description of FIG. 17 andillustrating the rollers or helpers which guide the roller sheet fromstation No. 3 into the succeeding dies of station No. 5 and initiate thebending of the lateral portions upwardly at the break line incooperation with the fixed die;

FIG. 21 is a diagrammatic vertical sectional view taken at station No. 5of the embodiment identified in the description of FIG. 17 andillustrating the cooperation between the rotary dies and the fixed diesto bend the lateral portions sharply upwardly;

FIG. 22 is a diagrammatic vertical sectional view taken at station No. 6of the embodiment identified in the description of FIG. 17 andillustrating the use of the roller guides to further bend the lateralportions upwardly and inwardly to a point adjacent the lateral portionsof the upper sheet;

FIG. 23 is a diagrammatic vertical sectional view taken at station No. 7of the embodiment identified in the description of FIG. 17 andillustrating the cooperation of rotary dies to form the sealing lip atthe lateral edge of the upper sheet and the bringing of the lateralportions of the lower sheet to a truly vertical position inwardly of thelip;

FIG. 24 is a diagrammatic vertical sectional view taken at station No. 8of the embodiment identified in the description of FIG. 17 andillustrating the cooperation of rotary dies to bring the sealing lip toa vertically extending position at the end of the sealing element of thelower sheet and in position to be sealed;

FIG. 25 is a diagrammatic vertical sectional view taken at station No. 9of the embodiment identified in the description of FIG. 17 andillustrating the cooperation of rotary dies to bring the sealing lip ofthe upper sheet inwardly and around and below the sealing element of thelower sheet;

FIG. 26 is a diagrammatic vertical sectional view taken at station No.10 in the embodiment identified in the description of FIG. 17 andillustrating fixed cams which bring the lip into sealing positionbeneath and against the sealing element at the edge of the lower sheet;

FIG. 27 is a diagrammatic vertical sectional view of the embodimentidentified in the description of FIG. 17 and illustrating the manner inwhich the buttoning dies form the buttons in the seam to lock thesealing elements to each other;

FIG. 28 is a diagrammatic vertical sectional view on an enlarged scaletaken through the channel guides which support the upper metal sheetduring the formation of the embodiment identified in the description ofFIG. 17;

FIG. 29 is a diagrammatic fragmentary side elevational view of a dualcradle mechanism which may be carried by the frame to support twoseparate rolls of sheet metal in feeding relation to either of theduct-forming mechanisms in lieu of a single composite roll comprised ofa pair of such sheets;

FIG. 30 is a diagrammatic vertical sectional view taken through theembodiment of FIG. 1 and showing at station No. 10 structure which maybe added to flatten the seam against the sidewall of the duct in theevent such is desired;

FIG. 31 is a diagrammatic vertical sectional view taken through stationNo. I], which may be added to the combined structure shown in FIG. I andFIG. 30, illustrating the final step by means of which the seam isflattened against the sidewall of the duct;

FIG. 32 is a diagrammatic side elevational view showing the means bywhich the rotary dies illustrated in FIGS. 30 and 31 may be driven bythe same drive mechanisms as that shown in FIG. 2.

The preferred embodiment, as shown in FIGS. 1-16, include a movableframe F which is adapted to be moved to a desired location through theuse of rollers I at the lower end of a plurality of vertically extendingsupports 2. A cradle 3 rotatably supports a single roll 4 of a pair 5and 6 of metal sheets. These sheets are arranged in superimposedcontiguous relation with each other and rolled into a single roll sothat their convolutions are concentric. The upper sheet 5 is slightlywider than the lower sheet 6 and, as can be best seen in FIG. 3, theyenter the feeding and initial crimping mechanism, indicated generally bythe numeral 7, in vertically spaced relation as they unwind from theroll 4.

The frame F is elongated and has a pair of vertically extending sidemembers 8 which are transversely spaced from each other and carrysupport brackets 9, which in turn carry elongated transversely spacedfixed inner die members 10. These fixed inner die members 10, as shownin FIGS. 69, are comprised of elongated flat metal plates which protrudeforwardly beyond the brackets 9 a substantial distance, which can beseen by reference to FIG. 1.

If desired, a pair of separate rolls 11 and 12 (see FIG. 29) of sheetmetal may be utilized in lieu of the single composite roll 4. In thatevent, the rolls 11 and 12 are rotatably supported similarly to the roll4 upon a composite cradle 13, which utilizes saddles 14 and 15 torotatably support the shafts on which the rolls are carried. When dualrolls 11 and 12 are utilized, the upper sheet 15 is fed into the machinein vertically spaced relation to the lower sheet 16, as shown.

FIG. 1 shows the preferred embodiment of our duct-forming machine withthe various stations to be hereinafter referred to indicated thereonalong the length of the machine. It will be noted that station No. 1 ispositioned immediately adjacent the roll 4. This station No. 1, which isshown in greater detail in FIG. 3, utilizes a feeding and initialcrimping mechanism 7 which includes an upper set of rotary die members1'7 and 18, the upper one of which is rotatably mounted so as to becapable of vertical movement relative to the lower rotary die 18. Topermit such movement, each end of the die member 17 is rotatably mountedin a spring loaded bearing structure 19 at each of its ends, the detailsof which are clearly shown in FIG. 14. Thus, the upper roller 17 isconstantly urged downwardly by the action of spring members 20 whichpress the vertically slidable mounting block 21 and the shaft of theroller 17 downwardly toward engagement with the lower die 18, which ismounted for rotation about a fixed axis upon the frame F. i

The upper roller 17 has tapered metal end portions 22 and a majorintermediate portion 23, which is formed of a firm but resilientmaterial. The lower metal roller 18 has enlarged end portionscharacterized by a bevelled surface 24, which is complementary to thebevelled surface 22 of the upper roller 17, and a flat angular surface25 which extends parallel to and bears against the cylindrical endportion of the roller 17, so that when the two rollers 17 and 18 arebrought together these surfaces will function as cooperative rotarydies.

The outer surface of the roller 18 is characterized by a plurality ofangular radially outwardly extending circumferential beads 26, which arespaced longitudinally of the roller 18 and a pair of longitudinally andoutwardly extending ribs 27. These ribs 27 extend parallel to the axisof the roller 18 and are carried at its circumferential surface and aredisposed at opposite sides of the roller.

The lower set of cooperating rotary dies are adapted to receive andprogress the lower sheet of metal through the machine and they are thecounterpart of the rollers 17 and 18. The lower roller 28 of this set isconstructed similarly to the roller 17 and is similarly mounted forrotation and vertical movement in similar movable bearings, except thatthey are inverted so as to constantly urge the roller 28 upwardly towardthe cooperative rotary die 29 which, like the die 18, is mounted forrotation about a fixed axis on the frame F.

The rotary die 29 has angular beads 30 similar to the beads 26 andlongitudinally extending ribs 31 similar to the ribs 27. It also has abevelled surface 32 similar to the surface 24, but, as shown, it has nosurface comparable to the angular die surface 25. The relatively narrowlower sheet 6 obviates any need for such a surface. The rotary grippingmembers 17 and 28 are adjusted relative to the rotary die members 18 and29 through the use of a control system indicated generally by the letterC, which will be described in greater detail hereinafter.

When the two sheets of metal from the roll 4 have been inserted betweenthe members 17, 18 and 28, 29, they will be progressed thereby throughthe remainder of the machine, since they are each power driven, as willbe hereinafter described. The longitudinal ribs 27 and 31 and theangular beads 26 and 30 impart or form ribs on the surface of the flatsheets and provide added rigidity thereto. The cooperative bevelledsurfaces 22 and 24 form a 30 bend of the lateral or edge portions of thesheet 5, and the angular surface 25 shapes the extreme edge portions soas to extend parallel to the main body of the sheet, as will be readilyappreciated by reference to FIG. 3. This is the initial step inprogressively forming the outermore lateral portions of the upper sheetinto a sealing element which will ultimately become a portion of theseam. At the same time, the rotary die 29 imparts a bend to the narrowerlower sheet 6, at its extreme edge, of a 30 angle, there being no edgeportion left extending parallel to the main body of the sheet 6, sincethe sheet is narrower. Thus the extreme edge portion of the sheet 6 isbent downwardly and away from the sheet 5, just as the lateral portionsof the sheet 5 are bent away from the sheet 6.

From station No. l, the two sheets 5 and 6 move to station No. 2, atwhich location it enters the second stage of the ductforrning operation.At this location, as shown in FIG. 4, there is positioned a second pairof vertically spaced sets of cooperating rotary dies to impart furthershaping of the lateral portions of the sheets 5 and 6, so that theseaming elements will extend at a 60 angle relative to the main body ofthe sheets. At this station there is located an upper set of rotarydies, identified by the numerals 33 and 34. Each of these dies consistof a shaft rotatably mounted in the frame F and carrying a rotary diemember at each ofits ends and shaped so as to be complementary andcooperate with the die member of the other. Thus the rotary die 33 hasat each of its ends a die member having a flat annular surface 35 and abevelled 60 surface 26 and an enlarged cylindrical surface 37. The die34 has at each of its ends a rotary die having an annular surface 38 anda 60 bevelled surface 39 and an enlarged cylindrical surface 40. Asclearly shown in FIG. 4, the surface 35 cooperates with the surface 38and the surface 36 cooperates with the surface 39 to impart a 60 angleto the sealing element, and the surface 37 cooperates with thecylindrical surface 40 to maintain the very edge portion or lip 41parallel to the main body of the sheet 5.

The lower set of rotary dies, indicated generally by the numerals 42 and43, are similarly mounted and arranged, the die 42 being constructedidentically with the die 34. The lower rotary die 43 is constructedidentically with the upper rotary die 33, and they cooperate to impart a60 angle to the sealing element 44 at the very edge of the lower sheet6.

From station No. 2, which is shown in FIG. 4, the sheets 5 and 6 areprogressed to station No. 3, at which location there is disposed anothergroup of vertically spaced sets of driven rotary dies, mounted forrotation upon the frame F and spaced transversely thereof. As shown inFIG. 5, the upper set is comprised of a pair of cooperating rotary diesidentified generally by the numerals 45 and 46. These dies consist ofelongated shafts rotatably mounted upon the frame F and carrying at eachof its ends a cooperating rotary die member constructed and arranged toimpart additional shaping to the lateral portions of the sheets 5 and 6,preparatory to forming a rectangular duct therefrom. The rotary die 45has a die member at each of its ends, which has an annular surface 47separated from an outwardly tapering surface 48 by an annular groove 49.At the larger end of this die is an essentially flat surface 50, whichextends essentially normal to the shaft upon which these die members aremounted, and a reduced annular sur face 51 is provided outwardlythereof.

The die 46 carries at each of its ends a cooperative rotary die membercharacterized by an annular surface 52 separated from an outwardlydiminishing frustoconical surface 53 by an annular rib 54, which ispositioned to extend into the groove 49 as the die members rotate. Thisdie member is further characterized by a surface 55 which extendsessentially normal to the shaft of the die 46 and is positioned slightlyoutwardly of the surface 50 so as to cooperate therewith to impart aangle to the seam element 56. It is further characterized by an enlargedannular surface 57, which cooperates with the cylindrical surface 51 tocause the lip 41 to extend essentially normally to the sealing element56.

The lower set of rotary dies, identified by the numerals 58 and 59, aresimilarly constructed and arranged to shape the lower sheet 6. Therotary die 58 is constructed identically with the rotary die 46, and therotary die 59 is constructed identically to the rotary die 45, and theycooperate in a similar manner to impart the same shape to the lateralportions of the sheet 6, except, of course, that the extreme edgeportion, or sealing element 44, carries no lip element corresponding tothe lip element 41 because of its narrower width.

From station No. 3, which is shown in FIG. 5, the sheets move to stationNo. 4, at which they encounter the structure shown in FIG. 6. At stationNo. 4 the sheets reach a helper station at which they are guidedinwardly by a plurality of rotatably mounted rollers 60, each of whichis carried by a spindle or shaft 61 and is supported upon one oftransverse members 62 or 63 as shown in FIG. 6. It is at this stationthat the sheets 5 and 6 first encounter the fixed die member 10, whichare positioned so as to be disposed just inwardly of the break lines 64,which were imparted to the two sheets by the cooperative action of theannular ribs 54 and grooves 49 at station No. 3, as shown in FIG. 5. Itwill be noted that the rollers 60 are positioned so as to engage thelateral portions of the sheets 5 and 6 just inwardly of the sealingelement. These rollers 60 are not driven, but are free to rotate on theshaft 61, which in turn are adjustably mounted on the transverse members62 and 63 through the use of sleeves as shown. These rollers 60 guidethe lateral portions of the sheets and 6 inwardly toward each other soas to progressively break the sheets at the break line 64 and guide theminto the rotary dies at station No. 5, which are shown in FIG. 7.

FIG. 7 shows a plurality of driven rotary dies cooperating with thefixed dies 10. A power-driven upper shaft 65 is rotatably mounted uponthe frame F to extend transversely thereof and carries at each of itsend portions a rotary die member 66 having a cylindrical surface 67 anda 53 outwardly bevelled surface 68. Each of these rotary die members 66are positioned so that the cylindrical surface 67 bears upon the uppersheet 5 just inwardly of outer surface of the fixed die member and thebevelled surface is disposed just outwardly thereof so as to bring thelateral portions of the sheet member 5 inwardly 53 from the plane of thesheet. The shaft 65 also carries at each end a disk-shaped guidingmember 69, which rotates with the shaft and extends into the angleformed by the sealing element 56 so as to guide the outermore lateralportions of the sheet inwardly toward the sheet 6, as shown in FIG. 7.

A lower and similarly mounted shaft 70 carried identically constructedguide members 69 and a pair of rotary die members 71, which areconstructed and positioned similar to the rotary die member 66, exceptthat the angle of the bevel 72 is such as to impart a 57 angle to thelateral portions of the sheet 6 and thus move the sealing element 44inwardly at each side to an extent farther and ahead of the sealingelement 56 of the sheet 5. This arrangement is utilized in order toinsure that'upon further movement of the lateral portions of the twosheets inwardly the sealing elements will mate properly.

From station No. 5, as shown in FIG. 7, the sheets 5 and 6 move onwardlyto station No. 6, which is shown in FIG. 8. Here again, the sheetsencounter a helper station in the form of rollers 73, each of which isrotatably mounted for free rotation about a spindle 74 that is carriedby a sleeve 75 upon a transverse member such as 76 or 77. These rollers73 guide the lateral portions of the sheets 5 and 6 further inwardly asthey bend further at the break lines 64. It will be noted that therollers 73, which are carried by the lower transverse member 77, arepositioned inwardly slightly farther than diose carried by the uppermember 76 so that the sealing element 44 is disposed somewhat inwardlyof the sealing element 56 and the lip 41 at each side of the machine.Note that the two sheets 5 and 6 have been gradually and progressivelyformed in sequential steps into two oppositely facing channel memberswhich are essentially U-shaped in cross-sectional configuration. Asthese sheets continue to progress through the machine, even furtherbending takes place until a truly rectangular configuration is obtained.The effect of the rollers 73 is felt by the material of the sheets 5 and6 which is disposed thereahead so that the sheets are properly guidedinto the mechanism at station No. 7, which is shown in FIG. 9.

At station No. 7 there is provided a plurality of rotary die membersconstructed and arranged to close the rectangular configuration andcommence to close the lip 41 around the sealing elements 44 so as tohold the latter between it and the sealing element 56. Carried by theframe F at opposite sides of the fixed dies 10 and cooperating therewithis a pair of rotary die members which are identical in construction andidentified generally by the numeral 78. Each of these rotary die members78 has a cylindrical compressing surface 79 and a slightly bevelledinner end surface 80. The latter gradually bends the lateral portions ofthe sheet 5 inwardly to a 90 angle against the fixed die and at the sametime the cylindrical surface 79 brings the sealing element 56 and thelip. 41 downwardly and around the relatively inwardly disposed sealingelement 44. A pair of rotary die members indicated generally by thenumeral 81 is also carried by the frame F in position to cooperate withthe rollers 78 and toward that end they are constructed to provide abevelled camming surface 82, which engages the lip 41 and brings itinwardly to an angulatcd position relative to the sealing element 56 andsomewhat around and below the sealing element 44 of the sheet 6. Thusthe construction shown completes the 90 bend at the side of the duct andcom rncnces the closing of the seam member which ultimately consists ofthe two sealing elements 44 and 56 held in sealed position by thesealing element 41, as will be hereinafter described. It will be notedthat the two rotary die members 81 are positioned at opposite sides ofthe fixed die members 10 and have similar bevelled inner ends whichcomplete the 90 bend of the sheet 6 at the break line 64 in addition tocommencing the closing of the seam.

From position 7 as shown in FIG. 9, the sheets 5 and 6 move to stationNo. 8, at which they encounter the structure shown in FIG. 10. At thisstation there is provided at each of the sides of the now rectangularconfiguration additional camming structure constructed and arranged tocomplete the formation of the seam. As shown in FIG. 10, mounted uponthe frame F outwardly of the fixed dies 5, and in position to receivethe rein the seam elements 44 and 56 and the lip 41, is a pair ofcamming members 83 and 84. These camming members 83 and 84 are fixed andvertically spaced from each other a distance essentially equal to thecombined thickness of the elements 41, 44, and 56. The end portions ofthe camming members 83 and 84 which face toward the direction from whichthe sheets 5 and 6 move are somewhat flared as shown in the detailedview of FIG. 14 to facilitate entrance of these elements thereinto. Asthe sheets 5 and 6 are drawn past station No. 8, the seam which is nowcomprised of the seam elements 44 and 56 and the lip 41 is completed,the lip 41 being brought into flattened position around and below thesealing element 44 of the lower sheet 6. Elements 83 and 84 are providedat each side of the duct so that as the sheets pass thereby the seam iscompleted to the configuration shown in FIG. 10.

As the now rectangular configuration comprised of the sheets 5 and 6leave station No. 8 as shown in FIG. 10, it proceeds to station No. 9,which is shown in FIG. 11. At this station the seam at each side of theduct, which consists of the elements 41, 44, and 56in flattenedcondition, passes through one of a pair of vertically spaced rotary diemembers 85 and 86, one each of which is disposed at each side of theduct. Each of the rotary die members 85 is characterized by acylindrical surface 87, which bears against the outer surface of thesealing element 56 and a pair of recesses 88 which are oppositelydisposed within said cylindrical surface. A bevelled end surface 89 isalso provided to facilitate movement of the rectangular duct thereby.Each of the rotary die members 86 is characterized by a cylindricalsurface 90 which bears against the underside of the sealing lip 41 andcompresses the latter to flatten the seam and compress it. Each rotarydie member has a pair of outwardly extending buttons 91 which arepositioned so as to pass directly opposite the recesses 83 as theyrotate, and thus impart a locking button 92 at spaced locationsapproximately 3 inches apart along the seam to the metal of the elements41, 44, and 56, which make up the seam. This button 92 positively locksthe elements which make up the seam to each other and precludesseparation during subsequent handling of the duct. An enlarged detailedview of the button being formed is shown in FIG. 15.

FIG. 12 shows a diagrammatic perspective view which illustrates themanner in which the individual sheets of the roll 4 gradually movetherefrom through the machine and assume in sequential steps the shapewhich is illustrated at the locations identified thereon by numeralscorresponding to the stations hereinbefore described. Thus it can beseen that the two flat sheets of metal 5 and 6 are progressivelyconverted from flat sheets into a duct having a rectangularcross-sectional configuration as these sheets are drawn through themachine, the duct entering the machine at one end in the form of twosheets and being discharged from the opposite end in the form of acontinuous rectangular duct which can be constructed of any desiredpredetermined length merely by providing a roll having two such sheets 5and 6 of such desired length.

lines 129 and 130. At this station there is provided a transverse shaft136 which rotatably mounts by means of sleeves 137 and spindles 138, apair of guiding rollers 139 which rotate freely on the spindles. Theserollers 139 provide a function comparable to that provided by therollers 60 in station No. 4 of the first embodiment and, as will be seenby reference to FIG. 20, bring the lateral portion of the sheet 114upwardly and inwardly and guide the same into the dies at station No. 5,which is shown in FIG. 21.

At station No. in FIG. 21, the upper sheet 111 is still carried in thechannel members 119 and 120 and remains unmodified. The frame F carriesa transverse shaft 140 which rotatably mounts a pair of rotary dies suchas indicated by the numeral 141. Each of these dies has an annularsurface 142 and an outwardly bevelled surface 143 and is positioned sothat the latter surface engages the lateral portions of the sheet 114and bends them upwardly approximately 57 off the plane of the sheet 114.It will be noted that each is positioned so that the annular surface 142is disposed immediately below the fixed die members and the bevelledsurfaces 143 commence at the outer surface of these fixed die members.Also carried by the driven shaft 140 and disposed outwardly of therotary dies 141 is a pair of guiding disks or rollers indicatedgenerally by the numeral 144. These guiding rollers are bevelled to cometo an edge intermediate their axial ends and are shaped so as to engageand complement the edge portion of the sheet 114, the edge 145 of eachof these rollers extending into the angle formed by the sealing element118.

As the sheets leave station No. 5 which is shown in FIG. 21, they moveto station No. 6 which is shown in FIG. 22. At this station the uppersheet 111 still remains unmodified and is carried by the channel members119 and 120. A transversely extending shaft 146 is carried by the frameF and mounts by means of a sleeve 147 and a spindle 148, a freelyrotatable roller 149 at each of the outer sides of the fixed die 10. Thespindles 148 extend upwardly and slightly outwardly and position therollers 149 so as to bring the lateral portions of the sheet 114inwardly toward the fixed die members 110. These guide rollers 149 bringthe lateral portions to extend approximately 75 from the plane of thesheet 114 and guide the sheet into the mechanism of station No. 7, whichis shown in FIG. 23.

The channel members 119 and 120 terminate between stations No. 6 and No,7 and at station No. 7 sheet 111 is acted upon by a pair of rotary diesindicated generally by the numeral 150. This pair of rotary dies 150 ismounted upon a powered transverse shaft 151, which is carried by theframe F. Each of the rotary die members 150 cooperates with anotherrotary die member indicated generally by the numeral 152, which ispositioned immediately therebelow and supported upon a shaft 153 whichlikewise is powered and supported by the frame F. Each of the rotarydies 150 has an annular die surface 154 which terminates just short ofthe lateral edge of the sheet 111 and merges with an outwardly flaringdie surface 155, as shown in FIG. 23. The lower dies 152 have an annularsurface 156 which cooperates with the annular surface 154 and mergesinto a diminishing die surface 157 which cooperates with the flaring diesurface 155 to form the outer edge portion of the sheet 111 into anangulated lip 158. It will be noted that the break lines 129 and 130 arespaced a distance less than the width of the sheet 111 so that the lip158 is formed opposite the outer end of the sealing element 118 andextends downwardly thereby. It will also be noted that the inner ends ofthe rotary dies 152 are bevelled as at 159 to facilitate engagement andpassage of the lateral portions of the sheet 114 as the sheet movesthrough the machine. The rotary dies 152 function to move the lateralportions of the sheet 114 so that they extend normal to the centralportion of the sheet and are brought flush against the outer surface ofthe inner dies 10 to complete the rectangular configuration. They alsofunction to bring the sealing element 118 inwardly so that it will bepositioned inwardly of the lip 158.

As the two sheets 111 and 114 move from station No. 7, as shown in FIG.23, they proceed to station No. 8, which is shown in FIG. 24. It is atthis station that the sealing lip 158 is brought to vertically extendingposition and normal to the sealing element 118. This is accomplishedthrough the use ofa pair of rotary die members indicated generally bythe numeral 160, which are carried upon a transverse shaft 161 mountedfor rotation upon the frame F. This shaft 161 is powered to rotate thetwo dies at their position directly above the sealing element 118 andlip 158. Each of the dies 160 has an annular surface 162 and an adjacentradially extending surface 163 which extends outwardly therefrom at aposition just outwardly of the break at the inner end of the lip 158. Italso has an adjacent bevelled surface 164 which guides and earns the lip158 into position where the surface 163 can force a sharp break or bendat the base of the lip. Cooperating with each of the rotary dies 160 isone of a second pair of rotary dies indicated generally by the numeral165. Each of these dies is carried upon a shaft 166 which in turn ismounted upon the frame F and is likewise power driven as shown. Each ofthe dies has an annular die surface 167 which merges with a bevelledsurface 168 that extends inwardly therefrom and is adjacent to aradially extending die surface 169. The surface 169 engages the innersurface of the lip 158 and the annular surface 167 cooperates with theannular surface 162 while the bevelled surface 168 guides the lateralportions of the sheet 114 inwardly. It is at this station that thesealing lip is brought to a 90 orientation and the sealing element 118is brought snugly up against the undersurface of the sheet 111immediately adjacent this lip preparatory to forming a seam therewith. v

As the rectangular configuration shown in FIG. 24 leaves station No. 8,it moves toward station No. 9 which is shown in FIG. 25. It is at thisstation that the lip 158 is brought inwardly to a partially sealingposition. This is accomplished by a pair of rotary dies indicatedgenerally by the numeral 170 and carried by a power-driven shaft 171which is rotatably mounted on the frame F. The two rotary dies 170 arepositioned just outwardly of the two fixed die members 10 and arecharacterized by an annular surface 172 which bears against the uppersurface of the sheet 111 and cooperates with one of a pair of rotarydies indicated generally by the numeral 173. These rotary dies 173 arepositioned immediately below one of the dies 170 and are characterizedby a frustoconical camming surface 174 which terminates with a radiallyextending surface 175. These dies are mounted upon a shaft 176 whichlikewise is mounted upon the frame F. As these dies engage the lip 158,the end ofthe lip bears against the radial die surface of the die 173,and the outer surface of the lip 158 is cammed inwardly by thefrustoconical camming surface 174 in cooperation with the annularsurface 172 of the die 170. The inner end of the die 173 bears againstthe outer surface of the lateral portions of the sheet 114 which has nowbecome the sidewalls of the rectangular duct.

As the sheets leave station No. 9 which is shown in FIG. 25, they movetoward station No. 10, which is shown in FIG. 26. At station No. 10 theedge portions of the sheet 111 pass between a pair of camming members177 and 178 at each side of the rectangular duct. These camming membersare flared similarly to those shown in FIG. 15 and each pair issupported upon the frame F by brackets such as indicated by the numeral179. The camming members 177 and 178 compress the lip 158 around andupwardly against the underside of the sealing element 118 and cam theseelements tightly against the underside of the portion of the sheet 111which extends laterally beyond the sidewalls of the duct. This action ishighly similar to that described with respect to the preferredembodiment as is accomplished by the structure shown in FIG. 15.

As the duct leaves station No. 10 as shown in FIG. 26, it moves to thefinishing station shown in FIG. 27. At this finishing station there isprovided a transverse shaft 180 which is mounted upon the frame F forrotation and is powered, carries a pair of rotary die members indicatedgenerally by the The feeding and initial crimping mechanism shown inFIG. 3 and identified by the letter C is controlled through a handlemember 93 which is fixedly connected to rotate with a transverse shaft94 which is rotatably mounted and extends through the frame F. At eachend of the shaft 94 there is a cam member 95, the details of which areshown in FIG. 13. These earns 95 are fixed to the shaft 94 and rotatetherewith, and they have an irregular camming surface designed tocontrol the relative movement of the members 17 and 28 toward and awayfrom the rotary die members 18 and 29. This is accomplished through theuse of rollers or cam followers 96, which are carried at each end of themembers 17 and 28. Reference to FIG. 13 will disclose the irregularcamming surface of the earns 95.

The lever 93 and cam 95 are positioned in FIG. 13 so as to present thecamming surfaces having the maximum radius to the cam followers 96. Thisposition is identified as position No. 1 and, since the camming surfaces97 and 98 having the largest radius engage the cam followers 96 in thisposition, the upper roll 17 and the lower roll 28 will be positioned inopen position and in nonengaging relation to the rolls 18 and 29. Whilein this position the forward end of the lower sheet of metal 6 isinserted between the rolls 28 and 29 and the lever member 93 and theearns 95 are rotated about the shaft 94 to position No. 2, which is atthe camming surfaces identified by the numerals 99 and 100. It will benoted that the distance from the center of shaft 94 to the cammingsurface 99 is essentially equal to the distance between that shaft andthe camming surface 97 at position No. 1 and hence the upper roll 17will remain in open position. On the other hand, the distance from thecenter of shaft 94 to the camming surface 100 is substantially less thanthat between that shaft and the camming surface 98 at position No. 1 andhence the roll 28 will be moved by the springs 20 into engagement of theforward end of the lower sheet 6 to grip the same in cooperation withthe roll 29.

Once the sheet 6 has been gripped between the rolls 28 and 29, the lever93 and cams 95 may be rotated further until the camming surfacesidentified by the numerals 101, 102 bear against the cam followers 96.This is known as the rest position in which the rolls 28 and 29 areclosed and the rolls 17 and 18 are also closed. This is true because itwill be seen that the distance from shaft 94 to camming surface 102 hasbeen reduced sufficiently so that roll 17 is permitted to lower and gripthe forward end of the upper sheet which is extended therebetweenmanually just prior to movement of the lever to rest position, orposition No. 3. Further movement of the lever 93 sufficient to cause thecamming surfaces identified by the numerals 103 and 104 to engage thecam followers 96 (position No. 4) leaves the rolls 17 and 18 and 28 and29 in position holding the sheets and 6 in the same manner as in.position No. 3, but also closes an electrical switch which causes thedriving motor of the machine to be activated and rotate the rolls 17,18, 28 and 29 to cause the sheets 5 and 6 to be progressed through themachine.

In the event a flattened seam is desired, the frame F may be constructedof sufficient length to also carry the mechanisms shown in FIGS. 30-32,which will be described hereinafter. Description of the structure willbe made hereinafter subsequent to the description of the structuresshown in FIGS. 1729 inclusive.

FIGS. 17-29 illustrate a similar machine to that shown in FIGS. 1-16,except that the dies are constructed and arranged to form the seams atthe corners of the rectangular duct rather than at the intermediateportions of the sides of the duct. The same cradles may be utilized asdesired, but the roll of metal will be comprised of sheets of differentwidths as is shown in FIGS. 17-28. The same type of feeding and initialcrimping mechanism may be utilized except that the rolls will beconstructed differently. Thus in FIG. 1'], station No. 1 is shownwherein the vertically movable roll 110 is substantially shorter so asto conform to the narrower widths of the upper metal sheet 111. The roll110 is provided with a resilient intermediate portion and metal endportions comparable to the construction of the roll 17. The cooperatingroll 112 is com structed similarly to the roll 18, except that it, too.is shorter to conform to the narrower width of the upper sheet 111. Thelowest roll 113 is constructed similarly to roll 28, but it is longer inlength'to conform to the substantially greater width of the lower sheet114. The upper of the lower set of rolls 1 15 is constructed in the samemanner as roll 29, except that it, too, has a substantially greaterlength to conform to the greater width of lower sheet 4. The rolls 110,I12, I13, and 115 form the same functions of gripping and moving thesheets forwardly as do the rolls shown in FIG. 3. The rolls I13 and 115form a 30 angle of the edge portion of the sheet 114 in the same manneras the rolls 28 and 29 function. Since the rolls 110 and 112, however,do not have a bevelled end portion 22, the only effect these rolls haveupon the upper sheet 111 is to impart the transverse and longitudinalribs to the sheets to provided added rigidity in the same manner thatthe beads 26 and ribs 27 function upon the sheet 5.

FIG. 18 shows station No. 2 of the modified form of the invention. Asthe sheets pass through station No. l, as shown in FIG. 17, they enterthe structure shown in FIG. 18 for further modification corresponding tothat which takes place in station No. 2 of the preferred embodiment.Thus, the rolls 116 and 117 correspond to rolls 42 and 43, and'similarlyimpart a 60 angulation to the seal element 118 at each of the lateraledges of the sheet 114. The sheet 111 enters a pair of guiding channels119 and 120 which are supported by the frame F and extend longitudinallythereof at the central position shown. No modification of sheet 111takes place at station No. 2, and the only modification to sheet 114 isto impart a 60 angulation to the sealing element 118 and progress thesheet forwardly to station No. 3, which is shown in FIG. 19.

At station No. 3, the upper sheet 111 continues to ride within thechannel members 119 and 120, and no modification thereof is accomplishedat this station. The frame F carries at this station, however, a pair oftransverse shafts 121 and 122 which are power driven and carrycooperative rotary die members. At each end of the shaft 121 there is arotary die having a cylindrical surface 123 which is reduced to abevelled surface 124 and tapers gradually thereto as at 125. Each ofthese rotary die members cooperate with another rotary die member suchas 126 that is carried by the lower shaft 122. These rotary dies'l26have a somewhat bevelled end surface 127 which cooperate with thebevelled surface to move the sealing element 118 to extend normal to theimmediately adjacent lateral portion of the sheet 114. The surfaces 124and 128 cooperate to hold the material immediately adjacent the sealingelement 118 firmly.

Disposed inwardly of the rotary dies carried at the ends of the shafts121 and 122 are two pairs of cooperating dies which provide the initialbreak to the sheet 114 at break lines 129 and 130 which eventuallybecome the corners of the duct. The shaft 121 carries a pair ofidentical rotary dies 131, each of which is characterized by an annularcentrally disposed rib 132, and the adjacent surfaces of which slopeaway therefrom to a diminished radius, as clearly shown in FIG. 19.Cooperating with each of these dies 131 and carried by the shaft 122 inposition to form the break lines 129 and 130 is a pair of rotary diesindicated by the numeral 133. Each of these dies is characterized by anannular groove 134, which is centrally located intermediate the ends ofthe die and by an adjacent tapering surface which increases in radiusfrom the groove toward the outer end of the shaft and is indicated bythe numeral 135. As shown, these rotary dies cooperate to provide theinitial shaping of the sheet 114 toward a U-shaped construction adaptedto be closed eventually by the sheet 111.

As the sheets 111 and 114 leave station No. 3, they proceed towardstation No. 4, which is shown in FIG. 20. Here again the upper sheet 111continues to be carried by the channel members 119 and 120 withoutmodification thereto. It will be noted, however, that the fixed diemembers 10 are now disposed above the lower sheet 114 just inwardly ofthe break 13 numeral 181 each of which is characterized by an annularsurface 182 which has a pair of recesses 183 formed in its outersurface. These rotary dies 18] cooperate with a pair of rotary diesmounted immediately therebelow and identified generally by the numeral184. These dies likewise have an annular surface 185 which cooperatewith the annular surface 182 to further compress the seam formed by theelements 118 and 158 and further carry a pair of oppositely disposedoutwardly extending nipples 186 which are adapted to extend into therecesses 183 and form a button in the elements 118, 158, and the portionof the sheet 111 that extends outwardly beyond the sidewalls of theduct. In this manner, each of these elements is positively locked to theother to prevent separation during handling of the duct. Theconstruction of the button is similar to that shown in FIG. 16.

The detailed view of FIG. 28 merely shows the manner in which the sheet111 rides upon the channels 119 and 120 as hereinbefore described.

FIGS. 30-32 are shown herein to disclose the manner in which the seam ofthe first embodiment may be flattened, if such is desired. It will bereadily appreciated that if it is desired to flatten the seam of thesecond embodiment, it may be accomplished in the same manner by merelymoving the rotary die elements upwardly in position to engage the seamsat the comers and cam them downwardly. As shown, the seam can beflattened by adding a station immediately forwardly of station No. 9 ofthe first embodiment, the mechanism being comprised of two pairs ofcooperating rotary dies mounted upon the frame F in position to engagethe seam, the upper two dies identified by the numeral 187 beingprovided with a frustoconical die surface 188 which flares outwardly andcooperates with a lower die indicated generally by the numeral 189 whichcarries a frustoconical cooperating die surface 190. The cooperatingsurfaces 88 and 190 provide an initial bend to the seam so that itextends downwardly at approximately a 45 angle.

From station No. 10 as shown in FIG. 30 the duct moves to station No. 11as shown in FIG. 31 wherein the seam at each side of the duct engages aflattening die that is mounted for rotation on the frame F. Theseflattening dies 19] are characterized by a flat end surface 192 and anadjacent bevelled sur face 193 which together cooperate to engage andflatten the seam against the extension of the fixed inner die 10 asshown. The dies 188 and 190 and 191 can each be driven by a geararrangement such as is shown in FIG. 32 which may be incorporated in thedrive mechanism disclosed in FIG. 2.

FIG. 2 shows diagrammatically the gear train provided to drive thevarious rotary dies hereinbefore described so as to cause the metalsheets to be progressed through the various sequential stepshereinbefore described. A source of power (not shown) such as anelectric motor is connected in driving relation to a drive gear 195.This drive gear 195 is connected in driving relation to a second drivegear 196 which is rotatably mounted upon the frame F. A drive chain 197extends around the drive gear 196 in the manner shown to drive theinterengaging assembly of gears at the front and rear end of the frameF. The location of the various stations has been indicated in FIG. 2 byidentifying the various driving gears with the numerals of the shafts orrotary die members which they drive. It is believed that theinterrelation of these gears and the operation of the driving train willbe readily appreciated by anyone familiar with chain drives.

From the above it can be readily seen that we have provided a novelmachine which utilizes a plurality of rotary dies in such a manner thata pair of flat metal sheets may be fed into one end of the machine and acompletely constructed rectangular duct can be taken from the oppositeend as a result of an entirely automatic operation. Since the machine ismovable, it can be readily taken to any location where it is desired toutilize same, and, in fact, can be positioned adjacent an assembly linein a mobile home manufacturing plant, for example, so as to produce anddischarge rectangular ducts of any desired length and feed them directlyinto the partially constructed home as they pass our machine in theproduction line. A rectangular duct of any length desired can beproduced without difficulty and at a very substantial saving in cost,time and material. Moreover, there are no length limitations, and allthat is required to produce a duct of a prescribed length is to providea preprepared roll of a pair of sheets of that length and feed them intothe machine.

It will, of course, be understood that various changes may be made inthe form, details, arrangement and proportions of the parts withoutdeparting from the scope of this invention which consists of the mattershown and described herein and set forth in the appended claims.

What is claimed is:

1. A rectangular heat duct former capable of continuously forming arectangular duct of conventional heat duct crosssectional dimensions andof any appreciable length from pairs of rectangular sheets of metal,limited only by the length of such sheets, as they pass therethrough,comprising:

a. an elongated frame, and

b. rectangular duct-forming mechanism carried by said frame andconstructed and arranged to continuously form in progressive stagesducts which have rectangular heat duct cross-sectional dimensions andconfiguration from pairs of such rectangular sheets of metal as theypass through said mechanism, said duct-forming mechanism including:

1. two series of successive pairs of cooperative rotary die members 2.each of said series being disposed along one of a pair of spacedmetal-sheet paths extending longitudinally of said frame said pairs ofcooperative rotary die members of each of said series being mounted forrotation upon said frame at spaced locations along the length of saidframe and being constructed and arranged to engage the lateral portionsof such sheets at each side thereof to cooperatively and progressivelyshape each of such pairs of sheets into an elongated rectangular duct asthey pass longitudinally through said mechanism,

4. some of said pairs of cooperative rotary die members being alsodisposed at locations spaced transversely of said frame at oppositesides of such sheets in position to engage them at their lateralportions as they pass through said mechanism, and

5. progression means supported adjacent said series of ro tary diemembers and constructed and arranged to engage and move a pair of suchsheets of metal longitudinally through said mechanism in spaced relationto each other and in position to be engaged at their lateral portionsand so shaped by said cooperative rotary die members.

2. The structure defined in claim 1 wherein said progression means ispowered and rotary and constructed and arranged to engage each of suchsheets at various locations spaced transversely thereacross and inwardlyof their extreme lateral portrons.

3. The structure defined in claim 1, and a single roll of sheet metalsupported adjacent said duct-forming mechanism and comprised of a pairof elongated flat sheets of metal disposed in superimposed contiguousrelation and rolled into a single roll in concentric and contiguousconvolutions, the sheets thereof extending into said duct-formingmechanism and the lateral portions thereof being engaged by said rotarydie members in shaping relation.

4. The structure defined in claim 1 and a pair of separate rolls ofelongated flat sheets of metal supported adjacent said duct-formingmechanism. each of said sheets extending from one of said rolls intosaid duct-forming mechanism in juxtaposed relation and being engaged inshaping relation at their lateral portions by said rotary die members.

5. The structure defined in claim 1 wherein said rotary die members arearranged in vertically spaced sets.

6. The structure defined in claim 1 wherein some of said rotary dies arejuxtaposed relative to other of said dies with respect to such sheets ofmetal so as to engage and simuitaneously shape opposite lateral portionsof such sheets as they pass through said mechanism.

7. The structure defined in claim 1, wherein said duct-forrm ingmechanism also includes:

6. a fixed die member carried by said frame and extending longitudinallythereof, and

7. a plurality of rotary members rotatably mounted on said frameadjacent said fixed die member and constructed and arranged with respectthereto to engage and cooperatively shape lateral portions of suchsheets as the latter pass longitudinally through said mechanism andthereby form such sheets progressively along their length into a ducthaving a rectangular configuration.

8. The structure defined in claim 1, wherein said duct forming mechanismalso includes:

6. a fixed die member carried by said frame and extending longitudinallythereof, and

7. a plurality of camming members mounted on said frame adjacent saidfixed die member and constructed and arranged with respect thereto toengage and cooperatively shape lateral portions of such sheets as thelatter pass longitudinally through said mechanism and thereby form suchsheets progressively along their lengths into a duct having arectangular configuration.

9. The structure defined in claim 1 wherein said rotary die members arepower driven.

10. The structure defined in claim 1 wherein said forming mechanismincludes securing means for securing the adjacent lateral portions ofsaid sheets to each other.

11. The structure defined in claim 1 wherein said forming mechanismincludes securing means constructed and arranged to permanently lock theadjacent lateral portions of said sheets to each other after they havebeen so shaped.

12. The structure defined in claim 1 wherein said ductforming mechanismincludes seam-forming mechanism and said seam-forming mechanism includesrotary die members.

13. The structure defined in claim 1, wherein said ductforming mechanismincludes seam-forming mechanism carried by said frame.

14. The structure defined in claim 1 wherein said ductforming mechanismincludes seam-forming mechanism and seam-flattening mechanism, saidseam-flattening mechanism being constructed and arranged to flatten theseam formed by said seam-forming mechanism against the sidewall of therectangular duct formed by said duct-forming mechanism.

15. The structure defined in claim 1 wherein said ductforming mechanismincludes seam-forming mechanism and seam-flattening mechanism, saidseam-flattening mechanism including at least one rotary die member.

16. The structure defined in claim 1 wherein said ductforming mechanismis constructed and arranged to engage and shape such sheets intoelongated generally U-shaped channels facing each other with theirlateral portions extending toward each other to define a rectangularduct and includes rotary members constructed and arranged to form aninterlocking seam of said lateral portions intermediate the corners andat each of one of a pair of opposite sides of such rectangular ducts.

17. The structure defined in claim 1 wherein said ductforming mechanismis constructed and arranged to engage and shape such sheets intoelongated angulated channels facing each other with their lateralportions extending toward and adjacent each other to cooperativelydefine a rectangular duct and includes rotary members constructed andarranged to form an interlocking seam of said lateral portions adjacentone comer and at each one of a pair of opposite sides of suchrectangular ducts.

18. The structure defined in claim 1 wherein said ductforming mechanismincludes pairs of cooperating rotary die members constructed andarranged to engage and shape the outermore lateral portions of suchsheets into angular seamforming shapes, and also including additionalrotary die members spaced from and constructed and arranged behind saidfirst-mentioned die members to engage innermore lateral portions of suchsheets and shape the same into opposed adjacent channel members ofgenerally U-shaped configuration in cross section and facing each other.

19. A rectangular heat duct former capable of continuously forming arectangular duct of conventional heat duct crosssectional dimensions andof any appreciable length from pairs of rectangular sheets of metal,limited only by the length of such sheets, as they pass therethrough,comprising:

a. an elongated frame, and

b. rectangular duct-forming mechanism carried by said frame andconstructed and arranged to continuously form in progressive stagesducts which have rectangular heat duct cross-sectional dimensions andconfiguration from pairs of such rectangular sheets of metal as theypass through said mechanism, said duct-forming mechanism including:

. two series of successive pairs of cooperative rotary die members 2.each of said series being disposed along one of a pair of spacedmetal-sheet paths extending longitudinally of said frame said pairs ofcooperative rotary die members of each of said series being mounted forrotation upon said frame at spaced locations along the length of saidframe and being constructed and arranged to engage the lateral portionsof such sheets at each side thereof to cooperatively and progressivelyshape each of such pairs of sheets into an elongated rectangular duct asthey pass longitudinally through said mechanism,

4. some of said pairs of cooperative rotary die members being alsodisposed at locations spaced transversely of said frame at oppositesides of such sheets in position to engage them at their lateralportions as they pass through said mechanism,

5. progression means supported adjacent said series of rotary diemembers and constructed and arranged to engage and move a pair of suchsheets of metal longitudinally through said mechanism in spaced relationto each other and in position to be engaged at their lateral portionsand so shaped by said cooperative rotary die members, and

6. some of said pairs of cooperative rotary die members being alsodisposed at locations spaced from each other in at least two transversedirections relative to said frame.

20. The structure defined in claim 1? and a cradle mounted adjacent oneend of said frame and constructed and arranged to receive and support atleast one preprepared roll of a pair of elongated contiguous metalsheets in position to be fed into said duct-forming mechanism insuperimposed relation to each other.

21. The structure defined in claim 19 and cradle structure mountedadjacent one end of said frame and constructed and arranged to receiveand support a pair of rolls of elongated flat sheets of metal inposition to be fed into said duct-forming mechanism in superimposedrelation to each other.

22. The structure defined in claim 19 wherein said ductforming mechanismis constructed and arranged to engage and shape such sheets intoelongated generally U-shaped channels facing each other with theirlateral portions extending toward each other to define a rectangularduct and includes rotary members constructed and arranged to form aninterlocking seam of said lateral portions intermediate the corners andat each of one of a pair of opposite sides of such rectangular ducts.

23. The structure defined in claim 19 wherein said ductforming mechanismis constructed and arranged to engage and shape such sheets intoelongated angulated channels facing each other with their lateralportions extending toward and adjacent each other to cooperativelydefine a rectangular duct and includes rotary members constructed andarranged to form an interlocking seam of said lateral portions adjacentone corner and at each one of a pair of opposite sides of suchrectangular ducts.

24. The structure defined in claim 19 wherein said forming mechanismincludes cooperative fixed and rotary die members.

25. The structure defined in claim 19 wherein said feeding meansincludes a roller having a resilient sheet engaging surface.

26. The structure defined in claim 19 and rotary support memberssupporting said frame and adapting the same for ready movement of saidduct-forming mechanism and said frame from one manufacturing location toanother.

27. The structure defined in claim 19 wherein said pairs of rotary diemembers are disposed at multiple elevations upon said frame.

28. The structure defined in claim 19 and a pair of elongatedrectangular sheets of metal fed into said duct-forming mechanism inspaced relation to each other.

29. The structure defined in claim 19 wherein said ductforming mechanismincludes:

7. seam-forming mechanism carried by said frame and constructed andarranged to engage the extreme lateral portions of such sheets of metaland form a seam therefrom, and

8. seam-deforming mechanism carried by said frame and constructed andarranged to progressively deform portions of the seam so formed as suchsheets move through said mechanism to positively interlock mch seamportions.

30. The structure defined in claim 19 wherein said ductforming mechanismincludes:

7. afixed die member carried by said frame and extending longitudinallythereof, and

8. a plurality of camming rollers mounted on said frame for rotationabout nonparallel axes adjacent said fixed die member and constructedand arranged with respect thereto to engage and cooperatively shapelateral portions of such sheets as the latter pass longitudinallythrough said mechanism and thereby form such sheets progressively alongtheir lengths into a duct having a rectangular configuration.

31. The structure defined in claim 30 wherein said camming rollers aredisposed at a multiple oflevels.

32. The structure defined in claim 19 wherein said ductforming mechanismincludes:

7. a plurality of cooperative pairs of spaced rotary wallstiffening diescarried by said frame and constructed and arranged to receive suchsheets of metal therebetween and progressively form wall-stiffening ribsin such sheets as they pass longitudinally therethrough.

1. A rectangular heat duct former capable of continuously forming arectangular duct of conventional heat duct crosssectional dimensions andof any appreciable length from pairs of rectangular sheets of metal,limited only by the length of such sheets, as they pass therethrough,comprising: a. an elongated frame, and b. rectangular duct-formingmechanism carried by said frame and constructed and arranged tocontinuously form in progressive stages ducts which have rectangularheat duct cross-sectional dimensions and configuration from pairs ofsuch rectangular sheets of metal as they pass through said mechanism,said ductforming mechanism including:
 1. two series of successive pairsof cooperative rotary die members
 2. each of said series being disposedalong one of a pair of spaced metal-sheet paths extending longitudinallyof said frame
 3. said pairs of cooperative rotary die members of each ofsaid series being mounted for rotation upon said frame at spacedlocations along the length of said frame and being constructed andarranged to engage the lateral portions of such sheets at each sidethereof to cooperatively and progressively shape each of such pairs ofsheets into an elongated rectangular duct as they pass longitudinallythrough said mechanism,
 4. some of said pairs of cooperative rotary diemembers being also disposed at locations spaced transversely of saidframe at opposite sides of such sheets in position to engage them attheir lateral portions as they pass through said mechanism, and 5.progression means supported adjacent said series of rotary die membersand constructed and arranged to engage and move a pair of such sheets ofmetal longitudinally through said mechanism in spaced relation to eachother and in position to be engaged at their lateral portions and soshaped by said cooperative rotarY die members.
 2. each of said seriesbeing disposed along one of a pair of spaced metal-sheet paths extendinglongitudinally of said frame
 2. each of said series being disposed alongone of a pair of spaced metal-sheet paths extending longitudinally ofsaid frame
 2. The structure defined in claim 1 wherein said progressionmeans is powered and rotary and constructed and arranged to engage eachof such sheets at various locations spaced transversely thereacross andinwardly of their extreme lateral portions.
 3. said pairs of cooperativerotary die members of each of said series being mounted for rotationupon said frame at spaced locations along the length of said frame andbeing constructed and arranged to engage the lateral portions of suchsheets at each side thereof to cooperatively and progressively shapeeach of such pairs of sheets into an elongated rectangular duct as theypass longitudinally through said mechanism,
 3. said pairs of cooperativerotary die members of each of said series being mounted for rotationupon said frame at spaced locations along the length of said frame andbeing constructed and arranged to engage the lateral portions of suchsheets at each side thereof to cooperatively and progressively shapeeach of such pairs of sheets into an elongated rectangular duct as theypass longitudinally through said mechanism,
 3. The structure defined inclaim 1, and a single roll of sheet metal supported adjacent saidduct-forming mechanism and comprised of a pair of elongated flat sheetsof metal disposed in superimposed contiguous relation and rolled into asingle roll in concentric and contiguous convolutions, the sheetsthereof extending into said duct-forming mechanism and the lateralportions thereof being engaged by said rotary die members in shapingrelation.
 4. The structure defined in claim 1 and a pair of separaterolls of elongated flat sheets of metal supported adjacent saidduct-forming mechanism, each of said sheets extending from one of saidrolls into said duct-forming mechanism in juxtaposed relation and beingengaged in shaping relation at their lateral portions by said rotary diemembers.
 4. some of said pairs of cooperative rotary die members beingalso disposed at locations spaced transversely of said frame at oppositesides of such sheets in position to engage them at their lateralportions as they pass through said mechanism,
 4. some of said pairs ofcooperative rotary die members being also disposed at locations spacedtransversely of said frame at opposite sides of such sheets in positionto engage them at their lateral portions as they pass through saidmechanism, and
 5. progression means supported adjacent said series ofrotary die members and constructed and arranged to engage and move apair of such sheets of metal longitudinally through said mechanism inspaced relation to each other and in position to be engaged at theirlateral portions and so shaped by said cooperative rotarY die members.5. progression means supported adjacent said series of rotary diemembers and constructed and arranged to engage and move a pair of suchsheets of metal longitudinally through said mechanism in spaced relationto each other and in position to be engaged at their lateral portionsand so shaped by said cooperative rotary die members, and
 5. Thestructure defined in claim 1 wherein said rotary die members arearranged in vertically spaced sets.
 6. The structure defined in claim 1wherein some of said rotary dies are juxtaposed relative to other ofsaid dies with respect to such sheets of metal so as to engage andsimultaneously shape opposite lateral portions of such sheets as theypass through said mechanism.
 6. a fixed die member carried by said frameand extending longitudinally thereof, and
 6. a fixed die member carriedby said frame and extending longitudinally thereof, and
 6. some of saidpairs of cooperative rotary die members being also disposed at locationsspaced from each other in at least two transverse directions relative tosaid frame.
 7. seam-forming mechanism carried by said frame andconstructed and arranged to engage the extreme lateral portions of suchsheets of metal and form a seam therefrom, and
 7. a fixed die membercarried by said frame and extending longitudinally thereof, and
 7. aplurality of camming members mounted on said frame adjacent said fixeddie member and constructed and arranged with respect thereto to engageand cooperatively shape lateral portions of such sheets as the latterpass longitudinally through said mechanism and thereby form such sheetsprogressively along their lengths into a duct having a rectangularconfiguration.
 7. a plurality of rotary members rotatably mounted onsaid frame adjacent said fixed die member and constructed and arrangedwith respect thereto to engage and cooperatively shape lateral portionsof such sheets as the latter pass longitudinally through said mechanismand thereby form such sheets progressively along their length into aduct having a rectangular configuration.
 7. The structure defined inclaim 1, wherein said duct-forming mechanism also includes:
 7. aplurality of cooperative pairs of spaced rotary wall-stiffening diescarried by said frame and constructed and arranged to receive suchsheets of metal therebetween and progressively form wall-stiffening ribsin such sheets as they pass longitudinally therethrough.
 8. Thestructure defined in claim 1, wherein said duct-forming mechanism alsoincludes:
 8. a plurality of camming rollers mounted on said frame forrotation about nonparallel axes adjacent said fixed die member andconstructed and arranged with respect thereto to engage andcooperatively shape lateral portions of such sheets as the latter passlongitudinally through said mechanism and thereby form such sheetsprogressively along their lengths into a duct having a rectangularconfiguration.
 8. seam-deforming mechanism carried by said frame andconstructed and arranged to progressively deform portions of the seam soformed as such sheets move through said mechanism to positivelyinterlock such seam portions.
 9. The structure defined in claim 1wherein said rotary die members are power driven.
 10. The structuredefined in claim 1 wherein said forming mechanism includes securingmeans for securing the adjacent lateral portions of said sheets to eachother.
 11. The structure defined in claim 1 wherein said formingmechanism includes securing means constructed and arranged topermanently lock the adjacent lateral portions of said sheets to eachother after they have been so shaped.
 12. The structure defined in claim1 wherein said duct-forming mechanism includes seam-forming mechanismand said seam-forming mechanism includes rotary die members.
 13. Thestructure defined in claim 1, wherein said duct-forming mechanismincludes seam-forming mechanism carried by said frame.
 14. The structuredefined in claim 1 wherein said duct-forming mechanism includesseam-forming mechanism and seam-flattening mechanism, saidseam-flattening mechanism being constructed and arranged to flatten theseam formed by said seam-forming mechanism against the sidewall of therectangular duct formed by said duct-forming mechanism.
 15. Thestructure defined in claim 1 wherein said duct-forming mechanismincludes seam-forming mechanism and seam-flattening mechanism, saidseam-flattening mechanism including at least one rotary die member. 16.The structure defined in claim 1 wherein said duct-forming mechanism isconstructed and arrangEd to engage and shape such sheets into elongatedgenerally U-shaped channels facing each other with their lateralportions extending toward each other to define a rectangular duct andincludes rotary members constructed and arranged to form an interlockingseam of said lateral portions intermediate the corners and at each ofone of a pair of opposite sides of such rectangular ducts.
 17. Thestructure defined in claim 1 wherein said duct-forming mechanism isconstructed and arranged to engage and shape such sheets into elongatedangulated channels facing each other with their lateral portionsextending toward and adjacent each other to cooperatively define arectangular duct and includes rotary members constructed and arranged toform an interlocking seam of said lateral portions adjacent one cornerand at each one of a pair of opposite sides of such rectangular ducts.18. The structure defined in claim 1 wherein said duct-forming mechanismincludes pairs of cooperating rotary die members constructed andarranged to engage and shape the outermore lateral portions of suchsheets into angular seam-forming shapes, and also including additionalrotary die members spaced from and constructed and arranged behind saidfirst-mentioned die members to engage innermore lateral portions of suchsheets and shape the same into opposed adjacent channel members ofgenerally U-shaped configuration in cross section and facing each other.19. A rectangular heat duct former capable of continuously forming arectangular duct of conventional heat duct cross-sectional dimensionsand of any appreciable length from pairs of rectangular sheets of metal,limited only by the length of such sheets, as they pass therethrough,comprising: a. an elongated frame, and b. rectangular duct-formingmechanism carried by said frame and constructed and arranged tocontinuously form in progressive stages ducts which have rectangularheat duct cross-sectional dimensions and configuration from pairs ofsuch rectangular sheets of metal as they pass through said mechanism,said duct-forming mechanism including:
 20. The structure defined inclaim 19 and a cradle mounted adjacent one end of said frame andconstructed and arranged to receive and support at least one prepreparedroll of a pair of elongated contiguous metal sheets in position to befed into said duct-forming mechanism in superimposed relation to eachother.
 21. The structure defined in claim 19 and cradle structuremounted adjacent one end of said frame and constructed and arranged toreceive and support a pair of rolls of elongated flat sheets of metal inposition to be fed into said duct-forming mechanism in superimposedrelation to each other.
 22. The structure defined in claim 19 whereinsaid duct-forming mechanism is constructed and arranged to engage andshape such sheets into elongated generally U-shaped channels facing eachother with their lateral portions extending toward each other to definea rectangular duct and includes rotary members constructed and arrangedto form an interlocking seam of said lateral portions intermediate thecorners and at each of one of a pair of opposite sides of suchrectangular ducts.
 23. The structure defined in claim 19 wherein saidduct-forming mechanism is constructed and arranged to engage and shapesuch sheets into elongated angulated channels facing each other withtheir lateral portions extending toward and adjacent each other tocooperatively define a rectangular duct and includes rotary membersconstructed and arranged to form an interlocking seam of said lateralportions adjacent one corner and at each one of a pair of opposite sidesof such rectangular ducts.
 24. The structure defined in claim 19 whereinsaid forming mechanism includes cooperative fixed and rotary diemembers.
 25. The structure defined in claim 19 wherein said feedingmeans includes a roller having a resilient sheet engaging surface. 26.The structure defined in claim 19 and rotary support members supportingsaid frame and adapting the same for ready movement of said duct-formingmechanism and said frame from one manufacturing location to another. 27.The structure defined in claim 19 wherein said pairs of rotary diemembers are disposed at multiple elevations upon said frame.
 28. Thestructure defined in claim 19 and a pair of elongated rectangular sheetsof metal fed into said duct-forming mechanism in spaced relation to eachother.
 29. The structure defined in claim 19 wherein said duct-formingmechanism includes:
 30. The structure defined in claim 19 wherein saidduct-forming mechanism includes:
 31. The structure defined in claim 30wherein said camming rollers are disposed at a multiple of levels. 32.The structure defined in claim 19 wherein said duct-forming mechanismincludes: